Learning Materials
Features
Discover
Chapter 7: Q3 (page 350)
Critical ValueFor the survey described in Exercise 1 鈥淐elebrities and the Law,鈥� find the critical value that would be used for constructing a 99% confidence interval estimate of the population proportion.
The critical value that would be used for constructing a 99% confidence is 2.576.
Over 30 million students worldwide already upgrade their learning with 91影视!
All the tools & learning materials you need for study success - in one app.
Get started for free
Chickenpox : You plan to conduct a survey to estimate the percentage of adults who have had chickenpox. Find the number of people who must be surveyed if you want to be 90% confident that the sample percentage is within two percentage points of the true percentage for the population of all adults.
a. Assume that nothing is known about the prevalence of chickenpox.
b. Assume that about 95% of adults have had chickenpox.
c. Does the added knowledge in part (b) have much of an effect on the sample size?
Bootstrap Sample Given the sample data from Exercise 2, which of the following are not possible bootstrap samples?
a. 12, 19, 13, 43, 15
b. 12, 19, 15
c. 12, 12, 12, 43, 43
d. 14, 20, 12, 19, 15
e. 12, 13, 13, 12, 43, 15, 19
Critical Thinking. In Exercises 17鈥�28, use the data and confidence level to construct a confidence interval estimate of p, then address the given question.
Lipitor In clinical trials of the drug Lipitor (atorvastatin), 270 subjects were given a placebo, and 7 of them had allergic reactions. Among 863 subjects treated with 10 mg of the drug, 8 experienced allergic reactions. Construct the two 95% confidence interval estimates of the percentages of allergic reactions. Compare the results. What do you conclude?
Sample Size. In Exercises 29鈥�36, find the sample size required to estimate the population mean.
Mean IQ of Attorneys See the preceding exercise, in which we can assume that for the IQ scores. Attorneys are a group with IQ scores that vary less than the IQ scores of the general population. Find the sample size needed to estimate the mean IQ of attorneys, given that we want 98% confidence that the sample mean is within 3 IQ points of the population mean. Does the sample size appear to be practical?
Determining Sample Size. In Exercises 31鈥�38, use the given data to find the minimum sample size required to estimate a population proportion or percentage.
Astrology
A sociologist plans to conduct a survey to estimate the percentage of adults who believe in astrology. How many people must be surveyed if we want a confidence level of 99% and a margin of error of four percentage points?
a. Assume that nothing is known about the percentage to be estimated.
b. Use the information from a previous Harris survey in which 26% of respondents said that they believed in astrology.
What do you think about this solution?
We value your feedback to improve our textbook solutions.
Explanations 
Textbooks 
Flashcards 
91影视 AI 
Notes 
Study Plans 
Study Sets 
Find a degree 
Magazine